1. Field of the Invention
This invention relates to a process for producing silicon carbide. More particularly it relates to a process for producing silicon carbide by subjecting a specified organosilicon compound to hydrolysis to obtain a hydrolyzate, followed by calcining this hydrolyzate.
2. Description of the Related Art
In recent years, sintered silicon carbide having a high strength, superior heat resistance, oxidation resistance and abrasion resistance has come to be obtained so that is has found application not only to abrasive materials, refractories, heating elements utilizing semiconductivity, etc., but also to mechanical parts and structural units such as engines for automobiles, mechanical seals, etc. have been developed. Further, its fibers and whiskers have been used as a raw material for fiber-reinforcing composite materials or as other reinforcing materials and also have been utilized for forming heat-resistant and abrasion-resistant protective films.
As to the process for producing silicon carbide, a number of production processes have so far been disclosed such as reduction of silica with carbon (Japanese patent publications Nos. Sho 58-20885/1983 and Sho 58-48487/1983), reaction of silica with carbon (Japanese patent publication No. Sho 55-29005/1980, Japanese patent application laid-open No. Sho 60-77114/1985), decomposition-reaction of a silicon-containing gas with a carbon-containing gas by means of plasma (Japanese patent application laid-open No. Sho 57-175718/1982), reaction of a silicon-containing gas with a carbon-containing gas by means of plasma (Japanese patent publication No. Sho 58-25045/1983), a process of subjecting an alkoxysilane compound to gas phase reaction, followed by heat treatment (Japanese patent application laid-open No. Sho 61-44708/1986), etc.
However, any of these conventional processes have the following drawbacks. Difficulty in uniform mixing of two or more kinds of powdery solids in liable to have a bad influence upon the yield and purity of product. A high initial cost is required corresponding to gas reaction at high temperatures or by-production of corrosive gas. In the case of gas phase reaction, since the reaction is instantaneously carried out under severe conditions, carbon remains or the yield is inferior. To be effective for such gas-phase reactions, the respective raw materials should be previously gasified, and in some case, they should be uniformly mixed with the atmospheric gas, followed by feeding these so as not to cause a turbulent flow. Further, handling of a cohesive high temperature gas is troublesome.